When chosing "Visual Studio xxxx Win64" in CMake as target platform for the C# shared libraries, two preprocessor directives are not properly set to "WIN64" resulting in a failing build process:
Utilities\socketxx\socket++\fork.cpp, line 11
Common\gdcmWin32.h, line 23
As a result of the second, gdcmCommon has no exports defined and no gdcmCommon.lib file is created - which is later missing for gdcmDICT, gdcmMSFF etc.
Additionally I changed in CMake directly:
=== CMAKE_CXX_FLAGS ===
/DWIN32 /D_WINDOWS /W3 /GR /EHsc
/DWIN64 /D_WINDOWS /W3 /GR /EHsc
=== CMAKE_C_FLAGS ===
/DWIN32 /D_WINDOWS /W3
/DWIN64 /D_WINDOWS /W3
Having done so allows a successful build of 64bit DLLs.